Drafting instrument.



H. S. PECK.

DRAFTING INSTRUMENT.

Patented 00t.17,1916.

APPLICATION FILED MAR. 16. BIS- q INTI A whim INVENTOR A TTUR/VEY WITNESSES:

HARRY S. PECK, 0F FORT SMITH, ARKANSAS.

DRAFTING INSTRUMENT.

Specification of Letters Patent.

Application filed March 16, 1915. Serial No. 14,773.

To all whom it may concern:

Be it known that I, HARRY S. PEoK, a citizen of the United States, residing at Fort Smith, in the county of Sebastian and State of Arkansas, have invented certain new and useful Improvements in Drafting Instruments, of which the following is a specification.

My invention relates to improvements in drafting instruments, and more particularly to a. device adapted for use in scribing parallel lines.

The object of the invention is to provide a device of the character described in which the scribing members may be operated simultaneously or independently to secure the desired distance therebetween, and consequently, the distance between the lines which it is proposed to draw; to provide a device which when once set will maintain the initial distance of the marking points without any likelihood of becoming altered during ordinary usage, and to provide a device whichis extremely simple in operation and construction and economical to manufacture.

T o the accomplishment of the recited objects and others coordinatetherewith, the preferred embodiment of my invention resides in that construction and arrangement shown in the accompanying drawings, hereinafter described and embraced within the scope of the appended claims.

Broadly, my invention comprises a stationary leg and a pair of movable legs, each leg having a suitable marking device at its lower extremity, and all the legs at their upper extremities being connected to a common head which in turn carries a handle for the purpose of facilitating manipulation of the entire device; in combination with a screw threaded bar disposed transversely of the legs and connected to pivotal sockets in the movable legs, whereby the latter may be simultaneously adjusted toward or away from each other at will. In addition, I employ means for securing an independent adjustment of the legs as well asmeans for regulating the marking devices to compensate for the change in angularity of the movable members.

In the drawings: Figure 1 is a front elevation of the device embodying my invention. Fig. 2 is a side elevation of the instrument; and Fig. 3 is a vertical sectional elevation taken along lines 3-3 of Fig. 1.

Referring more particularly to the drawtion, the numerals 1, 2 and 3 designate three legs, each carrying a suitable marking device as 4 at its lower end, and all of the legs terminating at their upper ends in a head or cross piece 5 to which is attached a handle 6. For the purpose of clarity indescribing by mvention I will designate the outer legs 1 and 3 as movable members, and the intermediate leg 2 as a stationarymember. At

a point substantially medially of the longitudmal extent of each movable member I form a lateral enlargement 7 for the pur threads upon the right hand extremity. Furthermore, at the center of the bar there Patented Oct. 17, 1916.

, ings for a detailed description of my invenis arranged a thumb wheel or screw 11, andv a slight distance beyond this screw I have mounted a circular flange as 12, the portion of the bar between the screw and flange being unthreaded and the stationary member 2 being disposed therebetween. The marking devices 4 carried by the movable members are angularly deflected in such relation that they will be caused to scribe within certain limits the pro-per lines when the instrument is being used, but to compensate for any marked change in the angularity of the legs, I provide a pivotal connection 13 in combination with a set-screw 14 at points just above the lower extremity of each movable member.

When certain contingencies arise, it will be found advantageous to have some means whereby an independent adjustment of the.

legs may be had; and with this inmind I have a pair of small screw bars 15 and 16 having their inner adjacent terminals pivoted in the slot 17 of the central stationary leg, as at 18, and extending outwardly through the movable legs. bearing against the outer faces of the legs, are mounted upon the bars for locking the legs when the required adjustment has been attained. j 1

Set screws 19, Y

In operation, after it has been determined just what distance will be required between the lines, the entire instrument is grasped and the thumb wheel 11 turned in the appropriate direction either to cause the outer members 1 and 3 to reoede from or draw toward the stationary member 2. of the fact that the threads upon the right hand extremity of the bar 9 are of greater pitch than the threads upon the opposite extremity of said bar, it will be readily seen that as the bar is turned the outer members will be simultaneously moved in this proportionate relationship. When the desired distance between the members has been finally secured, one of the outer marking devices may be placed along a straight edge and the instrument then drawn to produce the three parallel lines, which, in this instance will be of unequal distances apart. Now when occasion should require an inde pendent adjustment either or both of the set-screws 19 can be readily operated, and

' if at any time the normal deflection of the marking devices is not such as to produce the true distances between the lines, the disposition of the free extremities of the movable legs may be. altered by loosening the set-screws 1a, constraining the extremities either outward or inward and then tightening the set-screws to preserve the proper relation.

It should be understood that in broader aspects the invention comprehends the em ployment not only of the various means described but all equivalent means for per forming the recited functions. It is desired to be understood that I do not limit myself to the precise construction shown and described. For example, the device may be so arranged that the outer members will move simultaneously and equal distances with respect to the stationary member, or that the degrees of movements of the outer members may be varied at will.-

WVhat is claimed is:

1. A drafting instrument comprising a permanent stationary member, a pair of movable members, each of said members carrying a marking device, and means extending through said movable members adapted when operated to cause them to move at different speeds with respect to said stationary member.

By virtue 2. A drafting instrument comprising a stationary member, a pair of movable members disposed at different distances from said stationary member, each of said members carrying 'a marking device, and means for varying the distance between the movable members with respect to the stationary member and for simultaneously maintaining the same proportional distances between all of said members.

3. A drafting instrument comprising a slotted stationary member, a pair of movable members, each of said members carrying a marking device, each movable member having a pivoted socket, and means operating in said slot and sockets for varying the distances between the movable members with respect to the stationary member.

4. A drafting instrument comprising a stationary member, a pair of resilient movable members, each of said members carrying a marking device, each movable member having a pivoted socket, and a threaded bar extending through all of the members and operable in said sockets for simultaneously varying the distances of the movable members with respect to the stationary member.

5. A. drafting instrument comprising a stationary member, a pair of movable members disposed at unequal distances relative Said first mentioned member, each of said members carrying a marking device, and means for varying the distances between the movable members and the stationary member and for simultaneously maintaining the same unequal proportional distances therebetween.

6. A drafting instrument comprising a stationary member, a pair of movable members, each of said members carrying a marl;- ing device, means for varying the distance between the movable members with respect to the stationary member and for simultaneously maintaining the same proportional distances between all of said members, and means for independently regulating the distance between said stationary member and each of said movable members.

In testimony whereof I hereunto a'ffix my signature in presence of two witnesses.

HARRY S. PECK.

WVitnesses W. A. VVITCHER, J. F. MCGRAW.

Copies of this patent may he obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G. 

